MovieStim3.seek

Coding
1

Hi everyone,

I have some issues with the seek() function. In my Experiment, the participants are presented with videos they can click on to play/pause. There is also the option to fast backword or forward 1 second or jumpt to the start of the Video by clicken on the corresponding button.

Playing/pausing and jumping to the beginning all work fine, but when I want to jump forward/backward for 1 second it takes 1-2 seconds for the experiment to react. I use the seek() function for the jumping and it seems that the jump takes longer, the higher the timestamp for the jump is (seek(1.0) seems quicker than seek(2.0) e.g.)
Do you have any Idea why the jumping takes so long? And is there an other function or way I could do the jumping that is faster, if it doesnt work with seek? The videos have 50 fps by the way if that is important.
Here is the relevant code for the jumping, but you can get a working experiment here:
[GitHub - Jonnyplate/PsychoPy_Experiment](Full Experiment)

               elif backbutton[i].contains(mouse):
                    ntime = max(mov[i].getCurrentFrameTime() - 1.0, 0.0)
                    mov[i].seek(ntime)
                elif forwardbutton[i].contains(mouse):
                    ntime = max(mov[i].getCurrentFrameTime() + 1.0, 0.0)
                    mov[i].seek(ntime)                   
                elif tobeginningbutton[i].contains(mouse):
                    mov[i].seek(0)

I am using the latest version of PsychoPy on a MacBook Pro with OS Mojave, 2,2 GHz Intel Core i7, 16 GB 1600 MHz DDR3, Intel Iris Pro 1536 MB
In addition to conducting the experiment offline with an EyeTracker it is supposed to go online via Pavlovia, so if you can think of anything that I should be aware of while coding to make it work both offline and online, I am happy for tips…

Thank you!

2

This is late, but, did you make any progress? Also, do the movies have audio?

I’m having a possibly related issue where fast framerates are causing disproportionate slowdown, and I’m wondering if this is related. Seek should be smarter than rendering each of the intermediary frames or re-loading the whole movie, but I’m not sure why else it would be faster to seek closer time-stamps.